The quantitative determination of analytes in body fluids is of great importance in the diagnoses and maintenance of certain physical conditions. For example, lactate, cholesterol and bilirubin should be monitored in certain individuals. In particular, it is important that individuals with diabetes frequently check the glucose level in their body fluids to regulate the glucose intake in their diets. The results of such tests can be used to determine what, if any, insulin or other medication needs to be administered. In one type of blood-glucose testing system, test sensors are used, to test a sample of blood.
A test sensor contains biosensing or reagent material that reacts with, for example, blood glucose. One type of electrochemical test sensor is a multilayer test sensor that includes a base or substrate and a lid. Another type of electrochemical test sensor includes a base, a spacer and a lid. Existing electrochemical test sensors include at least two electrodes in the form of an electrode pattern. A potential is applied across these electrodes and a current is measured at the working electrode. The current measurement is directly proportional to the size of the working electrode.
Electrodes in existing electrochemical test sensors are typically made of metallic materials that tend to be expensive. To reduce the cost, the electrodes are formed with a very thin thickness. By using thinner electrodes in a test sensor, the wear resistance of the electrodes is decreased. The practical effect of a reduced wear resistance is decreased robustness of the test sensor in processing as well as decreased robustness of the test sensor contact with the meter. This decrease in robustness also adds to the inability of these test sensors to be inserted into a meter opening more than once, while still providing an adequate contact with the meter contacts. Specifically, these thinner electrodes are also more prone to scratching during handling and insertion into the test-sensor opening of the meter. Test sensors are at least occasionally placed into a test-sensor opening more than once. For example, the user may fail to generate a useable amount of fluid before the meter times out and in such an instance, the user may reinsert the electrochemical test sensor back into the test-sensor opening of the meter instead of using a new sensor.
Therefore, it would be desirable to have an electrochemical test sensor and method of forming the same that improves the wear resistance thereof, while still being done in a cost-effective manner.